Joel Lake’s review published on Letterboxd:
The Rhythm Section is a revenge story led by a great performance by Blake Lively that could have benefitted from a more dynamic story instead of the predictable by the numbers plot that telegraphs every move the story takes and does so in such a meandering pace.
Blake Lively is putting in some great work here as her intensity in the action scenes feels real, the vulnerability in the more dramatic scenes feels earned and her chemistry with many of the other costars(Sterling K Brown for example) feels natural. Her character evolves in a great way too as it's easy to see the path she's taken to become the person she will turn into.
The story is just too predictable, too plodding and overall just doesn't serve the character or Blake Lively well at all.
This could have been a decent action series for Lively to helm. Sadly, she'll have to wait for the next big franchise to come knocking, but she definitely deserves the chance of the back of this performance alone.